DE69110747T2 - Facsimile machine. - Google Patents

Description

BACKGROUND OF THE INVENTION Field of the invention

The invention relates to a facsimile machine.

Description of the relevant state of the art

In recent years, facsimile machines have become widely used as image transmission devices. Since a facsimile machine uses a telephone line as a communication channel, a facsimile machine must be installed near a telephone line connection in a room. If the facsimile machine is installed away from the connection, it is necessary to install extension cables.

In order to eliminate such a positional limitation of a facsimile machine with respect to connection to a telephone line, it is possible to use what is called a cordless system which has recently been put into practical use in telephones and the like. In a cordless system, a facsimile machine is composed of a main device and a sub-device. The main device is connected to a telephone line and has a cordless transmission/reception circuit. On the other hand, the sub-device has a cordless transmission/reception circuit corresponding to the transmission/reception circuit of the main device and has a facsimile function unit including a scanner, a printer, a facsimile modem, a network control unit (NCU), etc. Signals are transmitted by radio transmission between the main and sub-devices. By the above arrangement, it is possible to eliminate the above limitation and to significantly improve the operability of the facsimile machine.

However, there is a limitation on the frequency band of radio signals transmitted between the main and sub-devices in the above-mentioned cordless system in order to prevent trouble due to noise and radio interference. The data transmission speed of the facsimile machine is limited by the frequency band limitation of the cordless system and the required frequency band determined by the type of modulation and demodulation process of the facsimile machine. In the case of facsimile transmission, the required frequency band is approximately 3 kHz, with a data transmission speed of 4800 bps (8-phase phase shift keying). This corresponds to the frequency band limitation of radio signals in a cordless system. However, if the data transmission speed is e.g. For example, since the maximum transmission speed is 9600 bps (Quadrature Amplitude Modulation (QAM)), in order to enable faster transmission, the required frequency band is wider than 3.4 kHz. This does not correspond to the frequency band limitation of the cordless system. Therefore, it is difficult to perform high-speed data transmission in a facsimile machine using a cordless system.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a facsimile apparatus which is free from positional restrictions and which can carry out data transmission at high speed over a telephone line.

In order to achieve the above object, there is provided a facsimile apparatus having a telephone function for transmitting and receiving audio signals through a telephone line and a facsimile function for transmitting and receiving image signals through the telephone line, which comprises a main device connected to the telephone line and provided with a telephone function, and a sub-device connected to the main device by radio and provided with a telephone function and a facsimile function.

The main device includes a storage device for temporarily storing image signals received via the telephone line and image signals received from the sub-device for transmission to the telephone line.

Since a facsimile apparatus according to the present invention is in the form of a cordless system having a sub-device and a main device connected to each other by radio communication, it is possible to install the facsimile apparatus at any location remote from the connection of a telephone line without laying extension cables, thereby improving the operability of the facsimile apparatus.

Furthermore, since signals transmitted through the telephone line and signals transmitted from the sub-device to the main device are temporarily stored in the storage device, it is possible to set the transmission speed to a value at which high-speed communication can be carried out through the telephone line without being limited by the frequency band of radio signals transmitted between the main device and the sub-device in the cordless system. As a result, the telephone charges are reduced and the busy state of the telephone line is shortened since the communication time period is shortened. is.

Further objects and advantages of the invention will become apparent from the following description, reference being made to the accompanying drawings in which a preferred embodiment of the invention is clearly shown.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a block diagram showing the structure of a facsimile apparatus according to an embodiment of the invention;

Fig. 2 is a flow chart for explaining the transmission operation of the facsimile machine of Fig. 1 and

Fig. 3 is a flow chart for explaining the receiving operation of the facsimile apparatus of Fig. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Fig. 1 is a block diagram showing the structure of a facsimile apparatus 1 according to an embodiment of the invention. The facsimile apparatus 1 constitutes what is called a cordless system, and comprises a main apparatus 3 connected to a telephone line 2 and a sub-apparatus 4 connected to the main apparatus 3 by radio communication. The main apparatus 3 has a cordless transmitting/receiving unit 5 for radio communication and a storage unit 6 for temporarily storing image signals to be transmitted to the telephone line 2 or the sub-apparatus 4. The sub-apparatus 4 has a cordless transmitting/receiving unit 5 for radio communication and a facsimile function unit 8 for carrying out transmission and reception of image data to another facsimile machine or from one such.

The structure of the main device 3 will now be described. The telephone line 2 is connected to a line control part 9 in the storage unit 6. The line control part 9 comprises an NCU (network control unit), a ring signal detection circuit, a CML relay, an automatic dialing signal transmission circuit, etc. When a signal transmitted through the telephone line 2 is detected by the ring signal detection circuit in the line control part 9, it is determined, for example, by detecting the presence of a signal CNG, whether the signal is a facsimile signal or a tone signal, and the CML relay is switched accordingly. One end of the CML relay is connected to a fax modem 10 in the storage unit 6, and the other end of the CML relay is connected to an audio processing circuit 11 in the cordless transceiver unit 5.

Facsimile signals transmitted over the telephone line 2 are supplied to the fax modem 10, which is connected to a main control circuit 12. The main control circuit 12 detects the signals from the fax modem 10, activates a memory control circuit 13, converts signals transmitted over the line control part 9 into binary signals in the fax modem 10, and temporarily stores the binary signals in a storage device such as an IC card or a floppy disk or a semiconductor memory 14 such as an SRAM or a DRAM. The memory 14 can be, for example, a digital audio tape recorder (DAT). After the transmitted facsimile signals are temporarily stored in the memory 14, they are read out again from the memory 14 and supplied to the cordless transmitter/receiver unit 5.

The facsimile signals read from the memory 14 and modulated by a frequency modulation modem 16 as well as the Audio signals transmitted through the telephone line 12 are supplied to the audio signal processing circuit 11 of the cordless transmitter/receiver unit 5. The audio signal processing circuit 11, which includes a limiting circuit and a compander (compression and expansion circuit), processes the audio signals received through the line control part 9 and audio signals received through a transmitter/receiver circuit 15. Furthermore, received control signals are supplied to a control circuit 17 through the modem 16. The control circuit 17 controls the operation of the main device 3 based on the control signals received through the modem 16 and on control signals received from the transmitter/receiver circuit 15.

An identification code (ID) assigned to each cordless system by the Minister of Posts and Telecommunications is stored in an ID-ROM 18 and is transmitted to the sub-device 4 for comparison when a radio link is established.

The transmitting/receiving circuit 15 comprises a receiving part and a transmitting part. The receiving part demodulates signals received from an antenna AT1 and supplies them to the audio signal processing circuit 11 and the control circuit 17. The transmitting part modulates signals received from the audio signal processing circuit 11 and the control circuit 17 and then transmits them from the antenna AT1 at a frequency of, for example, 254 MHz.

On the other hand, as described below, facsimile signals transmitted from the sub-device 4 to the main device 3 by radio communication are modulated in the fax modem 10 and then converted into binary signals and stored in the memory 14. Thereafter, the circuit of another facsimile machine is selected by an automatic dialing operation by the Transmission circuit for an automatic dialing process in the line control part 9 is opened and the facsimile devices are read out from the memory 14 and output.

Electrical voltage is supplied from a voltage source circuit 19 to the above-mentioned respective parts of the cordless transmitting/receiving unit 5.

The structure of the sub-device 4 will now be described. Facsimile signals, audio signals and control signals received by an antenna AT2 which is in radio communication with the main device 3 are supplied to a receiving part of a transmitting/receiving circuit 20 and demodulated there. The facsimile signals and the audio signals are supplied to an audio signal processing circuit 21 and the control signals are supplied to a control circuit 22. A transmitting part of the transmitting/receiving circuit 20 modulates the facsimile signals and the control signals from the audio signal processing circuit 21 and the control circuit 22 and transmits them from the antenna AT2 at, for example, 380 MHz. The control circuit 22 controls the operation of the sub-device 4 based on the control signals from the receiving part of the transmitting/receiving circuit 20, the control signals received from a modem 23, and key input signals from a keyboard 24.

An identification code (ID) assigned to each cordless system, assigned by the Minister of Posts and Telecommunications, is stored in an ID-ROM 25 and is transmitted to the main device 3 for comparison when a radio link is established.

The audio signal processing circuit 21 processes audio signals from the transmitting/receiving circuit 20 and control signals received from the control circuit 22 via the modem 23 and outputs them from a transmitter of a handset 26, and it processes audio signals from a receiver of the handset 26 and supplies them to the transmitting part of the transmit/receive circuit 20. The keyboard 24 has numeric keys and mode setting keys and it supplies a signal with an individual frequency to the control circuit 22 in response to each key input.

A voltage source circuit 27 applies electrical voltage to the above-mentioned respective parts of the cordless transmitting/receiving unit 7.

On the other hand, facsimile signals transmitted from the main device 3 by radio communication are supplied to a facsimile modem 28 of the facsimile function unit 8 via the modem 23 performing frequency modulation. The facsimile modem 28 is connected to a main control circuit 29 which identifies signals from the facsimile modem 28 and controls the operations of an operation part 30 and a mechanical control part 32. Furthermore, the main control circuit 29 controls the operation of an original reading part 31 and the mechanical control part 32 depending on the operation of the operation part 30 at the time of transmission of an image signal. Electric power is supplied to the main control circuit 29 from a power source circuit 23.

To record received facsimile signals, the mechanical control part 32 controls a receiving system drive circuit 25 based on signals from the fax modem 28 and drives a feed roller (not shown) to feed recording paper. Further, the mechanical control part 32 controls a recording control circuit 36 and drives a thermal head 37. Thus, the facsimile signals demodulated by the fax modem 28 are sequentially recorded by the thermal head 37 on recording paper fed in synchronism with the recording speed.

The operation part 30, which has numeric keys, a display, etc., carries out input processing and information display as required for image signal transmission.

On the other hand, the document reading part 31 optically reads the image to be transmitted on a document by means of a reading sensor including, for example, a charge-coupled device (CCD). A transmission system drive circuit 34 is controlled by the mechanism control part 32 based on the operation of the operation part 30. As a result, the feed roller is rotated and the document is moved while the image on the document is read. The image thus read is modulated by the fax modem 28 and transmitted as a facsimile signal by radio transmission through the cordless transmitting/receiving unit 7 to the main device 3. In this embodiment, the transmitted facsimile signals are temporarily stored in the memory 14 of the storage unit 6. After all the facsimile signals are transmitted to the memory 14 and stored therein, they are read out in sequence and output via the telephone line 2.

A telephone line terminal 39 is connected to the fax modem 28 via an NCU 38. The NCU 38 includes a ringing signal detection circuit, a CML relay, etc. Therefore, the facsimile function unit 8 itself can be used as a facsimile machine if the telephone line terminal 39 is directly connected to the telephone line 2 without forming a cordless system.

2 and 3 are flow charts for explaining the operation of the facsimile apparatus 1 according to this embodiment. Transmission functions of facsimile devices of the facsimile apparatus 1 will now be described with reference to FIG. 2. When a certain key in the operation part 30 is operated in a step a1, the original reading part 31 and the mechanism control part 32 are controlled in a step a2 so that a reading operation for the image to be transmitted is carried out.

Facsimile devices corresponding to the read image are transmitted from the sub-device 4 to the main device 3 by radio communication in a step a3. The transmitted signals are temporarily stored in the memory 14 in a step a4. In a step a5, it is determined whether or not the entire facsimile signals to be transmitted are stored in the memory 14. This determination is made based on a readout completion signal from the original reading section 31, a control signal from the memory control circuit 13, etc. If the determination result is negative, the process returns to step a2 and the above-mentioned procedure is repeated. When the storage for the entire facsimile signals is completed, the process proceeds to step a6, in which the telephone number of the other party is automatically dialed by the automatic dialing transmission circuit in the line control section 9. In a step a7, the line connection is made. Thereafter, the facsimile devices stored in the memory 14 are modulated by the fax modem 10 in a step a8 and successively output to the telephone line 2 at a speed (e.g. 9600 bps) that is equal to or higher than the transmission speed (e.g. 4800 bps) for the radio connection between the main and sub-devices.

Accordingly, in this embodiment, the facsimile devices to be transmitted are temporarily stored in the memory 14, a line connection is established by the automatic dialing function and then the image transmission is Without such an automatic dialing function, the operator cannot perform an input operation of a telephone number to another party until all the facsimile signals to be transmitted are stored in the memory 14. However, since the above-mentioned automatic dialing function enables the telephone number of the other party to be input in advance through the operation section 30, it is possible to perform the input operation of the telephone number of the other party before all the facsimile signals are stored in the memory 14.

The reception process for facsimile signals transmitted to the facsimile machine 1 will now be described with reference to Fig. 3. In a step b1, it is determined whether or not a ringing signal has been detected by the ringing signal detection circuit in the line control part 9. After a ringing signal has been detected, a connection to the line is made in a step b2. The facsimile signals received via the line control part 9 are converted into binary signals by the fax modem 10 in a step b3. The signals converted into binary signals by the fax modem 10 are stored in succession in the memory 14 in a step b4.

In a step b5, it is determined whether all the facsimile signals transmitted through the telephone line are stored in the memory 14. This determination is made based on a control signal from the other party, a control signal from the memory control circuit 13, etc. If the determination result is negative, the flow returns to step b3 and the above process is repeated. After the storage of all the facsimile signals is completed, the flow proceeds to a step b6 in which the facsimile signals stored in the memory 14 are transmitted in sequence at a speed (e.g., 4800 bps) lower than the transmission speed (e.g., 12800 bps). B. 9600 bps) of the telephone line 2 are transmitted from the main device 3 to the sub-device 4. Thereafter, the recording control circuit 36, etc. are activated in a step b7 by the mechanism control part 32 so that the demodulated facsimile signals are sequentially recorded on recording paper fed in synchronism with the recording speed. The invention is applicable to an image transmission apparatus and a data transmission apparatus in addition to a facsimile apparatus.

Many widely different embodiments of the invention may be made. It is to be understood that the invention is not limited to the specific embodiments described in this specification, except as defined in the appended claims.

Claims (4)

1. Facsimile machine (1) with telephone function for sending and receiving a sound signal via a telephone line (2), and with facsimile function for sending and receiving a picture signal via the telephone line, with: - a main device (3) connected to the telephone line (2) and having said telephone function and - a sub-device (4) connected by radio to the main device and having said telephone function and said facsimile function; - wherein the main device includes a storage device (6) for temporarily storing an image signal received via the telephone line (2) and an image signal received by the sub-device (4) and to be transmitted to the telephone line (2). 2. A facsimile apparatus according to claim 1, wherein each of the main device (3) and the sub-device (4) has a modulation/demodulation device (10) for converting a signal to be transmitted between the main device and the sub-device into a radio signal. 3. A facsimile apparatus according to claim 1, further comprising an automatic dialing function for automatically dialing a pre-registered telephone number by means of a predetermined procedure. 4. A facsimile apparatus according to claim 1, wherein the main device performs data transmission over the telephone line at a speed equal to or higher than the data transmission speed between the main and sub devices.